The invention is based on a vehicle suspension system as defined hereinafter. A vehicle suspension of this type is known (German Offenlegungsschrift No. 34 14 257) which is the same as U.S. Pat. No. 4,655,440.
With a suspension of the type described in said patent, the passage from one side of the shock absorber to the other is monitored by a valve device that is electromagnetically actuatable. This kind of semiactive suspension is markedly better than a passive suspension.
An active suspension, such as that known from German Offenlegungsschrift No. 27 38 455, has a high-pressure pump, a high-pressure reservoir and corresponding metering valves, and because all of these components must be designed for very high power (up to 5 kw per wheel), this type of suspension is very expensive and is uneconomical for conventional vehicles.
It is known that on a very good road, friction predominates in a vehicle suspension. Complicated and expensive control of a shock absorber is even less advantageous, the better the road and the greater the friction in the vehicle suspension.